Conventionally, a programmable logic controller (PLC) system is used as a system that controls industrial devices. The PLC system is configured from a combination of a plurality of units including a PLC unit. Also, by utilization of a communication unit, the PLC system can be connected to a remote system provided in a remote place through a network (see, for example, Patent Literature 1). The remote system is configured from a combination of a plurality of units. The PLC unit can control industrial devices to be controlled, which are connected to the respective units from which the remote system is configured, by controlling each of the units from which the remote system is configured through the network. In the following, the remote system will be referred to as a remote station and the PLC system to control the remote station will be referred to as a master station.
Here, a user executes assignment of a refresh device of the master station and assignment of a refresh device of the remote station by using a parameter setting function of an engineering tool. The assignment of the refresh device of the master station is to assign a PLC device to a communication memory. The assignment is to associate positions in both memories with each other. The assignment of the refresh device of the remote station is to assign a shared memory of each of the units from which the remote station is configured to a communication memory of the remote station. The result of the assignment of the refresh device of the master station is stored in the master station as a parameter of the master station and the result of the assignment of the refresh device of the remote station is stored in the remote station as a parameter of the remote station.